8.8.2 Dynamic properties of colloids (2) Diffusion and osmotic pressure 1905 Einstein proposed that D kRT rT f=frictional coefficient For spheric colloidal particles, XX Concentration gradient f= tnr Stokes'law Fickian first law for diffusion RT Einstein first law for D L6丌 r diffu uSIon D(2) Diffusion and osmotic pressure x Fickian first law for diffusion Concentration gradient = dn dc D dt dx  = − 1905 Einstein proposed that: Lf RT f k T D = = B For spheric colloidal particles, f = 6r Stokes’ law f = frictional coefficient L r RT D 6 1 = Einstein first law for diffusion 8.8.2 Dynamic properties of colloids